How would that work legally I wonder? If the copyright comes after a group already legally purchased the domain name, wouldn't the copyright either not be approved, or at least postponed until the domain expires? It seems like it would be legally unethical to force someone that has already purchased a property right to give it up because someone else claims copyright after the fact.
Personally, I doubt the bloomies care too much about the legalities. The FB page isn't a domain in itself, and it's not purchased, so I don't think there's any way to bring legal pressure to bear on the person that set up the page. FB could remove it though, if they felt there was some kind of copyright infringement, or for any other reason for that matter.
If this was an actual domain name, I think the owner would have every right to keep it, and the copyright owner would have every right to buy it . . .
Plus, "legally unethical" sounds like a redundancy . . .